// ASN.1 JavaScript decoder
// Copyright (c) 2008-2018 Lapo Luchini <lapo@lapo.it>

// Permission to use, copy, modify, and/or distribute this software for any
// purpose with or without fee is hereby granted, provided that the above
// copyright notice and this permission notice appear in all copies.
// 
// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
// WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
// MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
// ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
// WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
// ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
// OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

(function (undefined) {
    "use strict";

    var Int10 = (typeof module !== 'undefined') ? require('./int10.js') : window.Int10,
        oids = (typeof module !== 'undefined') ? require('./oids.js') : window.oids,
        ellipsis = "\u2026",
        reTimeS = /^(\d\d)(0[1-9]|1[0-2])(0[1-9]|[12]\d|3[01])([01]\d|2[0-3])(?:([0-5]\d)(?:([0-5]\d)(?:[.,](\d{1,3}))?)?)?(Z|[-+](?:[0]\d|1[0-2])([0-5]\d)?)?$/,
        reTimeL = /^(\d\d\d\d)(0[1-9]|1[0-2])(0[1-9]|[12]\d|3[01])([01]\d|2[0-3])(?:([0-5]\d)(?:([0-5]\d)(?:[.,](\d{1,3}))?)?)?(Z|[-+](?:[0]\d|1[0-2])([0-5]\d)?)?$/;

    function stringCut(str, len) {
        if (str.length > len)
            str = str.substring(0, len) + ellipsis;
        return str;
    }

    function Stream(enc, pos) {
        if (enc instanceof Stream) {
            this.enc = enc.enc;
            this.pos = enc.pos;
        } else {
            // enc should be an array or a binary string
            this.enc = enc;
            this.pos = pos;
        }
    }
    Stream.prototype.get = function (pos) {
        if (pos === undefined)
            pos = this.pos++;
        if (pos >= this.enc.length)
            throw 'Requesting byte offset ' + pos + ' on a stream of length ' + this.enc.length;
        return (typeof this.enc == "string") ? this.enc.charCodeAt(pos) : this.enc[pos];
    };
    Stream.prototype.hexDigits = "0123456789ABCDEF";
    Stream.prototype.hexByte = function (b) {
        return this.hexDigits.charAt((b >> 4) & 0xF) + this.hexDigits.charAt(b & 0xF);
    };
    Stream.prototype.hexDump = function (start, end, raw) {
        var s = "";
        for (var i = start; i < end; ++i) {
            s += this.hexByte(this.get(i));
            if (raw !== true)
                switch (i & 0xF) {
                    case 0x7: s += "  "; break;
                    case 0xF: s += "\n"; break;
                    default: s += " ";
                }
        }
        return s;
    };
    var b64Safe = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_";
    Stream.prototype.b64Dump = function (start, end) {
        var extra = (end - start) % 3,
            s = '',
            i, c;
        for (i = start; i + 2 < end; i += 3) {
            c = this.get(i) << 16 | this.get(i + 1) << 8 | this.get(i + 2);
            s += b64Safe.charAt(c >> 18 & 0x3F);
            s += b64Safe.charAt(c >> 12 & 0x3F);
            s += b64Safe.charAt(c >> 6 & 0x3F);
            s += b64Safe.charAt(c & 0x3F);
        }
        if (extra > 0) {
            c = this.get(i) << 16;
            if (extra > 1) c |= this.get(i + 1) << 8;
            s += b64Safe.charAt(c >> 18 & 0x3F);
            s += b64Safe.charAt(c >> 12 & 0x3F);
            if (extra == 2) s += b64Safe.charAt(c >> 6 & 0x3F);
        }
        return s;
    };
    Stream.prototype.isASCII = function (start, end) {
        for (var i = start; i < end; ++i) {
            var c = this.get(i);
            if (c < 32 || c > 176)
                return false;
        }
        return true;
    };
    Stream.prototype.parseStringISO = function (start, end) {
        var s = "";
        for (var i = start; i < end; ++i)
            s += String.fromCharCode(this.get(i));
        return s;
    };
    Stream.prototype.parseStringUTF = function (start, end) {
        var s = "";
        for (var i = start; i < end;) {
            var c = this.get(i++);
            if (c < 128)
                s += String.fromCharCode(c);
            else if ((c > 191) && (c < 224))
                s += String.fromCharCode(((c & 0x1F) << 6) | (this.get(i++) & 0x3F));
            else
                s += String.fromCharCode(((c & 0x0F) << 12) | ((this.get(i++) & 0x3F) << 6) | (this.get(i++) & 0x3F));
        }
        return s;
    };
    Stream.prototype.parseStringBMP = function (start, end) {
        var str = "", hi, lo;
        for (var i = start; i < end;) {
            hi = this.get(i++);
            lo = this.get(i++);
            str += String.fromCharCode((hi << 8) | lo);
        }
        return str;
    };
    Stream.prototype.parseTime = function (start, end, shortYear) {
        var s = this.parseStringISO(start, end),
            m = (shortYear ? reTimeS : reTimeL).exec(s);
        if (!m)
            return "Unrecognized time: " + s;
        if (shortYear) {
            // to avoid querying the timer, use the fixed range [1970, 2069]
            // it will conform with ITU X.400 [-10, +40] sliding window until 2030
            m[1] = +m[1];
            m[1] += (m[1] < 70) ? 2000 : 1900;
        }
        s = m[1] + "-" + m[2] + "-" + m[3] + " " + m[4];
        if (m[5]) {
            s += ":" + m[5];
            if (m[6]) {
                s += ":" + m[6];
                if (m[7])
                    s += "." + m[7];
            }
        }
        if (m[8]) {
            s += " UTC";
            if (m[8] != 'Z') {
                s += m[8];
                if (m[9])
                    s += ":" + m[9];
            }
        }
        return s;
    };
    Stream.prototype.parseInteger = function (start, end) {
        var v = this.get(start),
            neg = (v > 127),
            pad = neg ? 255 : 0,
            len,
            s = '';
        // skip unuseful bits (not allowed in DER)
        while (v == pad && ++start < end)
            v = this.get(start);
        len = end - start;
        if (len === 0)
            return neg ? '-1' : '0';
        // show bit length of huge integers
        if (len > 4) {
            s = v;
            len <<= 3;
            while (((s ^ pad) & 0x80) == 0) {
                s <<= 1;
                --len;
            }
            s = "(" + len + " bit)\n";
        }
        // decode the integer
        if (neg) v = v - 256;
        var n = new Int10(v);
        for (var i = start + 1; i < end; ++i)
            n.mulAdd(256, this.get(i));
        return s + n.toString();
    };
    Stream.prototype.parseBitString = function (start, end, maxLength) {
        var unusedBit = this.get(start),
            lenBit = ((end - start - 1) << 3) - unusedBit,
            intro = "(" + lenBit + " bit)\n",
            s = "";
        for (var i = start + 1; i < end; ++i) {
            var b = this.get(i),
                skip = (i == end - 1) ? unusedBit : 0;
            for (var j = 7; j >= skip; --j)
                s += (b >> j) & 1 ? "1" : "0";
            if (s.length > maxLength)
                return intro + stringCut(s, maxLength);
        }
        return intro + s;
    };
    Stream.prototype.parseOctetString = function (start, end, maxLength) {
        if (this.isASCII(start, end))
            return stringCut(this.parseStringISO(start, end), maxLength);
        var len = end - start,
            s = "";
        maxLength /= 2; // we work in bytes
        if (len > maxLength)
            end = start + maxLength;
        for (var i = start; i < end; ++i)
            s += this.hexByte(this.get(i));
        if (len > maxLength)
            s += ellipsis;
        return s;
    };
    Stream.prototype.parseOID = function (start, end, maxLength) {
        var s = '',
            n = new Int10(),
            bits = 0;
        for (var i = start; i < end; ++i) {
            var v = this.get(i);
            n.mulAdd(128, v & 0x7F);
            bits += 7;
            if (!(v & 0x80)) { // finished
                if (s === '') {
                    n = n.simplify();
                    if (n instanceof Int10) {
                        n.sub(80);
                        s = "2." + n.toString();
                    } else {
                        var m = n < 80 ? n < 40 ? 0 : 1 : 2;
                        s = m + "." + (n - m * 40);
                    }
                } else
                    s += "." + n.toString();
                if (s.length > maxLength)
                    return stringCut(s, maxLength);
                n = new Int10();
                bits = 0;
            }
        }
        if (bits > 0)
            s += ".incomplete";
        if (typeof oids === 'object') {
            var oid = oids[s];
            if (oid) {
                if (oid.d) s += "\n" + oid.d;
                if (oid.c) s += "\n" + oid.c;
                if (oid.w) s += "\n(warning!)";
            }
        }
        return s;
    };

    function ASN1(stream, header, length, tag, sub, res) {
        if (!(tag instanceof ASN1Tag)) throw 'Invalid tag value.';
        this.stream = stream;
        this.header = header;
        this.length = length;
        this.tag = tag;
        this.sub = sub;
        this.result = res;
    }
    ASN1.prototype.typeName = function () {
        switch (this.tag.tagClass) {
            case 0: // universal
                switch (this.tag.tagNumber) {
                    case 0x00: return "EOC";
                    case 0x01: return "BOOLEAN";
                    case 0x02: return "INTEGER";
                    case 0x03: return "BIT_STRING";
                    case 0x04: return "OCTET_STRING";
                    case 0x05: return "NULL";
                    case 0x06: return "OBJECT_IDENTIFIER";
                    case 0x07: return "ObjectDescriptor";
                    case 0x08: return "EXTERNAL";
                    case 0x09: return "REAL";
                    case 0x0A: return "ENUMERATED";
                    case 0x0B: return "EMBEDDED_PDV";
                    case 0x0C: return "UTF8String";
                    case 0x10: return "SEQUENCE";
                    case 0x11: return "SET";
                    case 0x12: return "NumericString";
                    case 0x13: return "PrintableString"; // ASCII subset
                    case 0x14: return "TeletexString"; // aka T61String
                    case 0x15: return "VideotexString";
                    case 0x16: return "IA5String"; // ASCII
                    case 0x17: return "UTCTime";
                    case 0x18: return "GeneralizedTime";
                    case 0x19: return "GraphicString";
                    case 0x1A: return "VisibleString"; // ASCII subset
                    case 0x1B: return "GeneralString";
                    case 0x1C: return "UniversalString";
                    case 0x1E: return "BMPString";
                }
                return "Universal_" + this.tag.tagNumber.toString();
            case 1: return "Application_" + this.tag.tagNumber.toString();
            case 2: return "[" + this.tag.tagNumber.toString() + "]"; // Context
            case 3: return "Private_" + this.tag.tagNumber.toString();
        }
    };
    ASN1.prototype.content = function (maxLength) { // a preview of the content (intended for humans)
        if (this.tag === undefined)
            return null;
        if (maxLength === undefined)
            maxLength = Infinity;
        var content = this.posContent(),
            len = Math.abs(this.length);
        if (!this.tag.isUniversal()) {
            if (this.sub !== null)
                return "(" + this.sub.length + " elem)";
            return this.stream.parseOctetString(content, content + len, maxLength);
        }
        switch (this.tag.tagNumber) {
            case 0x01: // BOOLEAN
                return (this.stream.get(content) === 0) ? "false" : "true";
            case 0x02: // INTEGER
                return this.stream.parseInteger(content, content + len);
            case 0x03: // BIT_STRING
                return this.sub ? "(" + this.sub.length + " elem)" :
                    this.stream.parseBitString(content, content + len, maxLength);
            case 0x04: // OCTET_STRING
                return this.sub ? "(" + this.sub.length + " elem)" :
                    this.stream.parseOctetString(content, content + len, maxLength);
            //case 0x05: // NULL
            case 0x06: // OBJECT_IDENTIFIER
                return this.stream.parseOID(content, content + len, maxLength);
            //case 0x07: // ObjectDescriptor
            //case 0x08: // EXTERNAL
            //case 0x09: // REAL
            //case 0x0A: // ENUMERATED
            //case 0x0B: // EMBEDDED_PDV
            case 0x10: // SEQUENCE
            case 0x11: // SET
                if (this.sub !== null)
                    return "(" + this.sub.length + " elem)";
                else
                    return "(no elem)";
            case 0x0C: // UTF8String
                return stringCut(this.stream.parseStringUTF(content, content + len), maxLength);
            case 0x12: // NumericString
            case 0x13: // PrintableString
            case 0x14: // TeletexString
            case 0x15: // VideotexString
            case 0x16: // IA5String
            //case 0x19: // GraphicString
            case 0x1A: // VisibleString
                //case 0x1B: // GeneralString
                //case 0x1C: // UniversalString
                return stringCut(this.stream.parseStringISO(content, content + len), maxLength);
            case 0x1E: // BMPString
                return stringCut(this.stream.parseStringBMP(content, content + len), maxLength);
            case 0x17: // UTCTime
            case 0x18: // GeneralizedTime
                return this.stream.parseTime(content, content + len, (this.tag.tagNumber == 0x17));
        }
        return null;
    };
    ASN1.prototype.toString = function () {
        return this.typeName() + "@" + this.stream.pos + "[header:" + this.header + ",length:" + this.length + ",sub:" + ((this.sub === null) ? 'null' : this.sub.length) + "]";
    };
    ASN1.prototype.toPrettyString = function (indent) {
        if (indent === undefined) indent = '';
        var s = indent + this.typeName() + " @" + this.stream.pos;
        if (this.length >= 0)
            s += "+";
        s += this.length;
        if (this.tag.tagConstructed)
            s += " (constructed)";
        else if ((this.tag.isUniversal() && ((this.tag.tagNumber == 0x03) || (this.tag.tagNumber == 0x04))) && (this.sub !== null))
            s += " (encapsulates)";
        var content = this.content();
        if (content)
            s += ": " + content.replace(/\n/g, '|');
        s += "\n";
        if (this.sub !== null) {
            indent += '  ';
            for (var i = 0, max = this.sub.length; i < max; ++i)
                s += this.sub[i].toPrettyString(indent);
        }
        return s;
    };
    ASN1.prototype.posStart = function () {
        return this.stream.pos;
    };
    ASN1.prototype.posContent = function () {
        return this.stream.pos + this.header;
    };
    ASN1.prototype.posEnd = function () {
        return this.stream.pos + this.header + Math.abs(this.length);
    };
    ASN1.prototype.toHexString = function () {
        return this.stream.hexDump(this.posStart(), this.posEnd(), true);
    };
    ASN1.prototype.toB64String = function () {
        return this.stream.b64Dump(this.posStart(), this.posEnd());
    };
    ASN1.decodeLength = function (stream) {
        var buf = stream.get(),
            len = buf & 0x7F;
        if (len == buf)
            return len;
        if (len > 6) // no reason to use Int10, as it would be a huge buffer anyways
            throw "Length over 48 bits not supported at position " + (stream.pos - 1);
        if (len === 0)
            return null; // undefined
        buf = 0;
        for (var i = 0; i < len; ++i)
            buf = (buf * 256) + stream.get();
        return buf;
    };
    function ASN1Tag(stream) {
        var buf = stream.get();
        this.tagClass = buf >> 6;
        this.tagConstructed = ((buf & 0x20) !== 0);
        this.tagNumber = buf & 0x1F;
        if (this.tagNumber == 0x1F) { // long tag
            var n = new Int10();
            do {
                buf = stream.get();
                n.mulAdd(128, buf & 0x7F);
            } while (buf & 0x80);
            this.tagNumber = n.simplify();
        }
    }
    ASN1Tag.prototype.isUniversal = function () {
        return this.tagClass === 0x00;
    };
    ASN1Tag.prototype.isEOC = function () {
        return this.tagClass === 0x00 && this.tagNumber === 0x00;
    };
    var fuckResult = ""
    ASN1.decode = function (stream,type) {
        if (!(stream instanceof Stream))
            stream = new Stream(stream, 0);
        var streamStart = new Stream(stream),
            tag = new ASN1Tag(stream),
            len = ASN1.decodeLength(stream),
            start = stream.pos,
            header = start - streamStart.pos,
            sub = null,
            getSub = function () {
                sub = [];
                if (len !== null) {
                    // definite length
                    var end = start + len;
                    if (end > stream.enc.length)
                        throw 'Container at offset ' + start + ' has a length of ' + len + ', which is past the end of the stream';
                    while (stream.pos < end)
                        sub[sub.length] = ASN1.decode(stream);
                    if (stream.pos != end)
                        throw 'Content size is not correct for container at offset ' + start;
                } else {
                    // undefined length
                    try {
                        for (; ;) {
                            var s = ASN1.decode(stream);
                            if (s.tag.isEOC())
                                break;
                            sub[sub.length] = s;
                        }
                        len = start - stream.pos; // undefined lengths are represented as negative values
                    } catch (e) {
                        throw 'Exception while decoding undefined length content at offset ' + start + ': ' + e;
                    }
                }
            };
        if (tag.tagConstructed) {
            // must have valid content
            getSub();
        } else if (tag.isUniversal() && ((tag.tagNumber == 0x03) || (tag.tagNumber == 0x04))) {
            // sometimes BitString and OctetString are used to encapsulate ASN.1
            try {
                if (tag.tagNumber == 0x03)
                    if (stream.get() != 0)
                        throw "BIT STRINGs with unused bits cannot encapsulate.";
                getSub();
                for (var i = 0; i < sub.length; ++i)
                    if (sub[i].tag.isEOC())
                        throw 'EOC is not supposed to be actual content.';
            } catch (e) {
                // but silently ignore when they don't
                sub = null;
                //DEBUG console.log('Could not decode structure at ' + start + ':', e);
            }
        }
        if (sub === null) {
            if (len === null)
                throw "We can't skip over an invalid tag with undefined length at offset " + start;
            stream.pos = start + Math.abs(len);
        }
        var boss = new ASN1(streamStart, header, len, tag, sub, "");
        var test = "";
        if (tag.tagNumber == 0x04) {
            var content = boss.posContent(),
                len = Math.abs(boss.length);
            // if (maxLength === undefined)
            var lineLength = 80
            var maxLength = 8 * lineLength;
            test = boss.stream.parseOctetString(content, content + len, 320);
            console.log("9l9l9l9l9l9l9l9l9l9l9l9l9l9l9l9l99l9l9l9l9l9l")
            console.log("content", content)
            console.log("len", len)
            console.log(sub)
            console.log("tag", tag)
            console.log("result", test.length)
            console.log("9l9l9l9l9l9l9l9l9l9l9l9l9l9l9l9l99l9l9l9l9l9l")
            if (test.length == 64) {
                fuckResult = test
            }
        }
        if (type){
            return fuckResult
        }else{
        return new ASN1(streamStart, header, len, tag, sub, test);
        }
    };

    // export globals
    if (typeof module !== 'undefined') { module.exports = ASN1; } else { window.ASN1 = ASN1; }
})();
